Topic:Altrenogest
Altrenogest is a synthetic progestin commonly used in horses to manage reproductive cycles and behaviors. It is primarily administered to mares to suppress estrus (heat) and synchronize ovulation, thereby facilitating breeding management. Altrenogest mimics the effects of the naturally occurring hormone progesterone, helping to regulate the estrous cycle and maintain pregnancy. In addition to its reproductive applications, altrenogest is sometimes used to address behavioral issues related to hormonal fluctuations. The compound is typically administered orally and requires careful dosing to ensure efficacy and safety. This page compiles peer-reviewed research studies and scholarly articles that explore the pharmacokinetics, therapeutic uses, and potential side effects of altrenogest in equine practice.
Outcomes of pregnant broodmares treated for colic at a tertiary care facility. To evaluate, following colic admission during pregnancy, (1) broodmare survival; (2) the frequency of recurrent colic in broodmares and its associated variables, and (3) pregnancy outcome and the variables associated with a negative pregnancy outcome. Methods: Ambidirectional observational cohort study. Methods: One hundred and four client-owned broodmare admissions. Methods: Admissions of pregnant mares from June 2010 until October 2016 were included. Data were collected until November 2017. Cox proportional hazards regression analysis was performed to evaluate variables associated with brood...
Pharmacokinetics of Intrarectal Altrenogest in Horses. Hospitalized pregnant mares being held nil per os (PO) because of medical or surgical events present a dilemma for pregnancy maintenance therapy, which commonly includes oral altrenogest. Rectal administration of medications is a recognized route for achieving systemic concentrations, but there are no data on the pharmacokinetics of rectal altrenogest administration in horses. The purpose of this study was to determine the pharmacokinetics of altrenogest following PO or per rectum (PR) administration in mares. Using a randomized two-way crossover study design, six horses received altrenogest (...
Effect of altrenogest-treatment of mares in late gestation on adrenocortical function, blood count and plasma electrolytes in their foals. Mares with compromised pregnancies are often treated with altrenogest to prevent abortion. However, there is only limited information about effects on the foal when altrenogest treatment is continued during final maturation of the fetus. Objective: To determine effects of altrenogest treatment during late gestation in mares on maturity, haematology changes, adrenocortical function and serum electrolytes in their newborn foals. Methods: Six mares were treated with altrenogest (0.088 mg/kg bwt) once daily from Day 280 of pregnancy until foaling and 7 mares served as controls. Results: Foals born...
Evaluation of the ability of altrenogest to control the equine estrous cycle. In our experience, altrenogest has not always been able to exert predictable control over the estrous cycle of the mare. Therefore, we examined 12 mares that were treated with altrenogest to identify reasons for its failure to control the estrous cycle. The mares were fed altrenogest for 15 to 20 days and were examined for follicle development, ovulation, and corpus luteum formation during treatment. Through the use of real-time ultrasonography and radioimmunoassay for progesterone, we concluded that altrenogest was unable to suppress the growth of follicles to preovulatory size in some mares,...
Exogenous hormone regimens to utilize successfully mares in dioestrus (days 2-14 after ovulation) as embryo transfer recipients. Two hormone regimens were utilized for recipient mares which were 2-14 days after ovulation at the time of non-surgical embryo transfer. In Exp. I, 20 embryos were transferred non-surgically into recipient mares which had been given 22 mg altrenogest daily starting the day of recipient ovulation. Higher (P less than 0.05) pregnancy rates (50% vs 0%) were obtained in mares which were 2-6 days after ovulation at the time of transfer compared with mares which were 7-12 days after ovulation. In Exp. II, on the day the donor mare ovulated (Day 0), 10 mg PGF-2 alpha were given to the recipient mare ...